Deposition of silica can be achieved from the vapor phase by chemical vapor deposition (CVD), sputtering or atomic layer deposition (ALD). ALD is a technique for growing controlled monolayers using self-limiting surface reactions with reactive vapor precursors, and sequentially growing such monolayers into a film of controlled thickness. A wide range of inorganic materials, including Al2O3, TiO2, ZnO, and ZnS can be grown as uniform layers of highly-controlled thickness 0.10˜0.20 nm per step. However, the high temperatures (i.e.; 150 to 800° C.) and vacuum conditions that are normally required can limit ALD for widespread use.